Eh, stupidity is a pretty good reason, but I don't think it's that. If it was then the line should be : "Climate change = Shits fucked and will get even more fucked, yo." That is a simple enough line to tout even to a heroin addict. Climate change isn't all that complicated as a concept (exact predictions, yes, but like, 'the color blue' is pretty easy a concept even though like photons and retinal pigments and neurons aren't). Hanlon's Razor is: "never attribute to conspiracy what you can attribute to stupidity". Well, stupidity isn't really cutting it anymore, so I think you can start to say conspiracy is a reasonable answer now too.